In wireless systems, paging is used when the network needs to contact a user terminal (UE) which is not currently communicating with the network or cannot communicate with the network—e.g. in a system using pagers having no communication possibility. For example, in wireless cellular telephone systems a UE is paged when it has gone into a mode where it uses discontinuous reception. There are generally two advantages associated with the use of paging for wireless cellular telephone systems:    It allows a mobile UE to move within a list of cells, typically within a Location Area, or from one radio coverage area to another without informing the network. This reduces the signalling traffic between UE's and the network which only deals with the position of the UE.    It allows a mobile UE in a particular cell or radio coverage area to use a reduced duty cycle when idle by only monitoring a paging channel, therefore reducing battery consumption.
The objective of paging is typically to contact the UE and to transfer a message. The message may include an implicit or explicit request for the UE to contact the network by sending a random access request on an access channel. In this way, communications can be set up between a mobile UE and the network.
Paging can be used towards individual UE's or to groups of UE's, typically as a notification channel in case of activity on a group call. In all these cases, paging is based on addressing, for example, a group address, a fleet address, an individual address, a set of individual addresses or addresses within a certain range or address segment. Either temporary of permanent addresses can be used.
Generally, the purpose of the paging is also indicated to the terminal e.g. for a mobile UE terminated phone call, a mobile terminated Short Message (SMS), an alpha-numeric message to be displayed on a pager.
Positioning or location techniques based on radio signal measurements in support of Location based services (LCS) are known for wireless cellular telecommunications systems, for example from the standard 3G TS 25.305 version 3.1.0 release 1999 “Functional Specification of Location Services”. A general description of location services and the service requirements is given in the specification 3G TS 22.071. Generally there are four categories of usage of the location service:    Commercial LCS (or Value Added Services);    Internal LCS (within the network);    Emergency LCS;    Lawful Intercept LCS.
Two basic techniques are used for determining the location of mobile user equipment:    a Mobile based, where the mobile UE can autonomously (e.g. using a Global Positioning System (GPS) receiver) or with the support of the network (through broadcast of information) calculates its position and transmits it to the network.    Network based, where the mobile UE reports measurements of radio signals and the network can perform the calculation of the mobile UE's position.
By measuring radio signals the capability to determine the geographic location of the user equipment (UE) can be provided. Locating the UE involves two main steps:    signal measurements; and    location estimate computation based on the measurements.The signal measurements may be made by the UE, a base station or a dedicated location measuring unit (LMU). The basic signals measured are typically radio transmissions, but some optional methods may make use of other transmissions such as general radio navigation signals. The location estimate computation may be made in the UE or by a calculation function located in the network. The location information may be requested by and reported to a client (application) associated with the UE, or by a client within or attached to the network. The location information may also be utilised internally within the network, for example, for location assisted handover or to support other features such as home location billing. There are many different possible uses for the location information. The location feature may be used internally by the network (or attached networks), by value-added network services, by the UE itself or through the network, and by “third party” services. The feature may also be used by an emergency service (which may be mandated or “value-added”), but the location service is not exclusively for emergencies.
These systems rely on a calculation of the mobile terminal's position which is calculated or recorded in the network. This method brings security problems—it is not always the case that a mobile user wants to have the location of the mobile identified by any service wishing to know it. Further, it takes up network resources to store the location of these equipments.
Positioning or location techniques have also been envisaged as a trigger to handovers, and also as means to support network planning i.e. having the UE report means to determine its position along with radio measurements so that the quality of reception can be logged by the network for each position of the mobile.
One method of determining the location of a UE is known as the Cell ID based method. A geographical area for a wireless cellular communications system is generally divided into separate radio coverage areas or cells. Generally a base station is located in each cell and a mobile user equipment (UE) communicates with one or more base station transceivers located in one or more cells during an active call. Generally, from a paging and network organisation point of view, several cells may be grouped together and referred to as a location area. Generally, the location of a UE within a location area is not known precisely. If a UE leaves a location area it will normally register itself with the new location area via the cell in which it is currently located (Location Updating). Both location areas and base stations generally have an identifier (LAI, Location Area Identifier and BSI, Base Station Identifier) which are generally transmitted on a common signalling channel). Except under special circumstances, the network does not know the position of the UE any more accurately than this. Hence, if the network wishes to make contact with the UE it generally sends a paging request on a suitable (usually common) signalling channel starting with the cells of the last location area in which the relevant UE registered. Location updating causes updating of subscriber data of the UE in question in the subscriber database, typically in a VLR, Visitor Location Register associated with a Mobile Exchange (MSC). Hence, it can be stated that the location updating procedure stores a location of each UE accessing the system. This results in a great deal of data to be stored continuously and the need for signalling at each location update. As the location area is made smaller, the amount of signalling increases as UE's move from one location area to the next at a higher frequency. For this reason location areas are typically rather large, usually several cells in size. Such a large size does not allow services to be provided which depend upon paging UE's in smaller areas, say 200 to 2000 meters in diameter.
Known systems in which the position of a mobile UE is determined by the network based on information from the mobile UE have the disadvantage that, if a large geographical area is involved, the positions of a large number of mobile UE's must be stored and continuously updated. This poses impractical limitations on implementing such a system for anything less than large areas. An example of this type of system is described in WO94/07337 in which a Temporary Paging Area reference is stored in the subscriber database.
The present invention has as an object, the provision of a system and method for organising a wireless communications system which allows notifications of a single user equipment or a group of user equipments within a specified geographical area.
A further object of the present invention is the provision of a system and method for organising a wireless communications system which allows notification of a group of user equipments within a specified geographical area which can be selectable in size without having to store and update the locations of the mobile UE's within the area.
A further object of the present invention is the provision of a system and method for organising a wireless communications system which allows a user to decide on whether the location of the user equipment is made known to the network.